Uber, Tinder, Snapchat, Twitter, and other top apps have allegedly been secretly tracking users, according to a report.

The Independent reported on Tuesday that the apps, which include Uber, Tinder, Skype, Twitter, Spotify, and Snapchat, “contain hidden trackers that can secretly monitor everything you do.”

“Publication of this information is in the public interest, as it reveals clandestine surveillance software that is unknown to Android users at the time of app installation,” declared Privacy Lab in a blog post. “These trackers vary in their features and purpose, but are primarily utilized for targeted advertising, behavioral analytics, and location tracking.”

Privacy Lab looked into 25 out of 44 identified trackers from French non-profit organization Exodus Privacy.

“Network activity originating from these Android apps crosses multiple countries and legal jurisdictions,” they claimed. “Lack of transparency about the collection, transmission, and processing of data via these trackers raises serious privacy concerns and may have grave security implications for mobile software downloaded and in active use by billions of people worldwide.”

In their report, Privacy Lab claimed, “More than 75% of the 300+ apps analyzed by Exodus contain the signatures of trackers,” while “apps identified as ‘clean’ today may contain trackers that have not yet been identified.”

“Perhaps more disconcerting is the potential impact of advertising trackers on the finances and healthcare of users. One app analyzed by Exodus, Mon AXA (‘My AXA’), is developed by a multinational insurance and financial firm, and was found to contain six trackers,” the organization alleged. “Exactly what information is shared is unknown, though the data stored by the app is extremely sensitive.”

Privacy Lab concluded their report by calling upon app developers and Google to be more transparent about privacy and security practices.

“Android users, and users of all app stores, deserve a trusted chain of software development, distribution, and installation that does not include unknown or masked third-party code,” they expressed. “Scholars, privacy advocates, and security researchers should be alarmed by the data, and can provide further analysis now that these findings and the Exodus platform have been made public.”

Last week, it was reported that regulators from both South Korea and the United Kingdom were investigating Google for allegedly collecting location data on its users without permission.